Many types of cleaning compositions are known for removing greases, tars, resins, waxes and many other contaminants from various surfaces. In general, these must act as solvents, or at least as softeners, for the material to be removed. Contaminants commonly include several ingredients, some of which are more difficult to remove or dissolve than others. Hence, it is quite a common practice to use very powerful solvents in cleaning compositions, particularly when the contaminants are particularly hard to remove. These may be used where there is no contact with the human body, but in other cases it is necessary to take stringent precautions so that the cleaning material will not cause injury to persons using it. The more powerful solvents, such as the lower ketones and mixed ketones, aldehydes, chlorinated hydrocarbons, certain of the lower acids and alcohols, and benzene type hydrocarbons and their derivatives are often highly injurious to the human skin or to sensitive organs of the body such as the eyes and/or the respiratory organs and other parts, particularly the mucosae. Many of these powerful solvents are quite toxic and they must be used only with body protection, often requiring complex ventilating systems and/or liquid proof gloves and other protective devices or clothing.
Another objection to many of the more effective solvents is that they will also remove or tend to remove paints, varnishes and other decorative or protective coatings from the surfaces with which they come into contact. This property of course often limits the usefulness of the more powerful solvents, such as the ketones, aldehydes, lower alcohols and acids, and some of the chlorinated solvents that are so often used. Such materials are used generally in combinations.
Among materials that have been particularly difficult to remove, and which must be removed without injury to human operators or to adjacent surface coatings, and the like, are such gummy or viscous materials as the residues of gel in so-called "jelly-filled" cables. These cables are used extensively in the communications industry, particularly for telephone trunk lines, underground lines and the like. The gel which is released, when the cables are cut or stripped for joining or branching, contaminates both the work and the worker and is quite obnoxious. Numerous solvents that might otherwise be employed for cleaning off such materials are too injurious to the skin of humans or to eyes or respiratory organs, or they may cause damage to painted, enameled or varnished surfaces, which rules out their use in many instances. Ordinary soap and water are not effective for removing materials such as those mentioned above.
Other types of resinous or gummy residue which are very hard to deal with, are the matrix materials commonly used by dentists for making dental prostheses. Being used in the human mouth, these materials cannot safely be removed by use of the more effective or potent solvents conventionally used for external purposes, because of toxicity and other harmful properties. Here again, the safer conventional materials are not sufficiently effective for cleaning such viscous residue materials from teeth, gums and other parts of the oral cavity.
Typical compositions which have been suggested in the prior art for cleaning some of the more difficult soluble residues include those disclosed in the U.S. Pat. No. 3,335,807 to Keers which describes compositions for removing epoxy and urethane type resinous contaminants. The patented compositions comprise combinations of chlorinated aliphatic hydrocarbons and chlorinated or non-chlorinated benzene and benzene derivatives; they also include oxygenated derivatives of benzene such as phenol and cresol. Most of these materials, and most benzene type compounds are quite toxic or unsafe for intimate skin contact or for inhaling, and they are altogether unsuitable for purposes of the present invention.
A particular object of the present invention is to produce a cleaning composition which will safely remove, especially, the gel residues from jelly-filled cables, and the viscous dental contaminants mentioned above without injury to personnel involved. Of course, the new compositions may also be used for many other purposes. The specific purpose mentioned requires the use of solvents of adequate dissolving power which are free or substantially free of the objectionable toxic properties mentioned above, i.e., which are not irritating to the human skin or to eyes or respiratory organs or to mucosae in general. The invention also involves the use of ingredients which will offset the tendency of many solvents to remove the natural lubricants from the human skin or which will replace such lubricants if they are removed to a significant extent. It also involves the use of a main carrier oil or base that in itself is not injurious to the body and preferably unobjectionable because of odor. It involves, further, the use of a surface active agent which will enhance and accelerate the dissolving action of the composition on the contaminant material. It is contemplated that the materials of the present invention will come into extensive contact with the human body.
Many references in the prior art use some of these ingredients and some of them use more than one of them in combination. Some of the more pertinent prior art references with which the applicant is familiar will be mentioned.
In U.S. Pat. No. 2,942,008 to Labowe, there is disclosed a solvent composition designed for use in cosmetic and pharmaceutical applications, as well as in industrial, which contains mixtures of animal or mineral oils along with lower aliphatic alcohols, the latter being solubilized in the oils by use of some of the higher fatty alcohols, such as oleyl, lauryl, myristyl and/or cetyl alcohols and the like. These materials, while largely nontoxic, do not have the solvent properties required by the present invention.
U.S. Pat. No. 3,131,153, to Klausner, describes a variety of products, including self-propellant sprays for various purposes, such as for cosmetics, lathers, and paint removers. These are made up, in general, of ketones, polyhydric alcohols, lower aliphatic mono-hydric alcohols, and the like, and the compositions may also include perfumes. Obviously, these products are not suitable for purposes of the present invention because they lack solvent power, although some ingredients are included which would be soothing or lubricating to the human skin.
U.S. Pat. No. 3,625,763, to Melillo, describes a composition for stripping resinous coatings of the epoxy type from substrates such as printed circuit boards. Ingredients named include polychlorinated aliphatic compounds, along with ketones and alcohols; several of the ingredients described are highly toxic to the human skin and to other sensitive body parts and the compositions as a whole would not be suitable for purposes of the present invention. U.S. Pat. No. 3,640,884, to Schofield et at., describes a cleaning and degreasing composition which involves the use of highly chlorinated and fluorinated hydrocarbons, such as tetrachlorodifluoroethane, along with acetic acid, or other acids, etc., and some lower alcohols. One of the uses suggested is to clean printed circuit boards of resinous materials. The ingredients described in the patent may be suitable for that purpose but they include toxic materials and apparently they would be injurious, also, to painted or varnished surfaces. U.S. Pat. No. 3,661,641, to Vigh et al. also describes a composition for removing resins of polyurethane type from printed circuit boards, using such ingredients as toluene, ethanol, propanol and methanol. Methanol is somewhat toxic and toluene is even more so; moreover, these rather volatile materials are not suitable for purposes of the present invention, not having the solvency and staying qualities desired for dissolving the particular materials mentioned above.
U.S. Pat. No. 3,714,049, to Charle et al., describes a sprayable aerosol type cleaner for removing stains from surfaces, particularly where the stains are caused by fatty substances. The reference suggests use of a combination of fluoro-chlorinated hydrocarbon propellants, such as trichloromonofluoromethane, along with trichloroethylene or turpentine, carbon tetrachloride, etc., and a finely divided solid absorbing powder, such as silica or talc. Aside from including some skin irritating ingredients that are named, the composition does not appear to be suitable for purposes of the present invention.
Thus, the prior art compositions of which applicant is aware do not appear to have been directed to a solution of the problems for which the composition of the present invention is particularly suited and designed. For purposes of the present invention, the composition must not be too volatile; it needs adequate solvent power but must be free of toxicity, it must prevent skin deoiling or restore the oils as they are removed, and it must be made up of materials which are not significantly irritating to eyes, respiratory tract, or other sensitive body parts, while accomplishing the required cleaning function rapidly and effectively.